inputs = input().strip().split()

num = float(inputs[0])
x = float(inputs[1])

result = 0

if num < 50:
    result = num * 0.53
    print(f"const = {result:.2f}")
else:
    result = 5.3 + (num - 50) * (0.53 + x)
    print(f"const = {result:.2f}")